1. Field of the Invention
This invention relates to a distillate fuel composition containing an oil soluble amine salt of a sulfonic acid and a low volatility carrier oil, and its use to reduce the formation of intake valve deposits in an internal combustion engine.
2. Description of Related Art
Various sulfonate salts have been used to reduce deposits in internal combustion engines. For example, U.S. Pat. Nos. 2,989,387 and 2,989,564 disclose that hydrocarbyl 1,3 diaminopropane sulfonates inhibit the formation of deposits when added to fuel and lubricating oils. U.S. Pat. No. 2,764,548 discloses that a fuel additive containing dinonyl naphthalene sulfonic acid salts (including ammonium and amine salts) provides lubrication at the tops of cylinders and at the valve stems. U.S. Pat. No. 2,995,427 describes an oil soluble ammonium sulfonate that prevents water accumulation in gasoline. U.S. Pat. No. 2,923,611 discloses that alkylene polyamine salts of either petroleum sulfonic acids or synthetic alkylated aromatic sulfonic acids are effective middle distillate fuel stabilizers. DS 1,545,248 discloses the use of oil and water soluble amine sulfonate salts as corrosion inhibitors in middle distillate fuels. U.S. Pat. No. 3,578,422 discloses the use of oil soluble ammonium or amine sulfonates to prevent or reduce water emulsion formation in petroleum distillate fuels. U.S. Pat. No. 3,785,790 discloses the use of polyisobutenyl N,N-dialkyl propylene 1,3-diamine alkylaromatic sulfonates to inhibit fouling in gasoline engines. U.S. Pat. No. 4,182,765 discloses a fungicide in oil products derived from the reaction of a quaternary ammonium salt and an alkyl benzene sulfonic acid. European Patent Application having Publication No. 0 261 957 discloses the use of a specific class of sulfonate salts as wax crystal modifiers for distillate fuels.
However, none of these patents suggest the particular synergistic fuel composition disclosed below or its effectiveness in reducing the formation of intake valve deposits in an internal combustion engine.